The energy regulator Ofgem agrees. “We’re confident that National Grid has the levers to manage the electricity system even in the most testing conditions,” it said.

National Grid has been forced to find increasingly inventive and expensive weapons to stave off power cuts. And despite its beefed-up armoury, it still risks sailing closer to the wind than is comfortable.

Another possibility is to import more electricity from Europe via sub-sea interconnectors or reduce the amount being exported to Ireland.

But not all of these measures are foolproof and most are expensive.

In a cold winter, it would be costly for the National Grid to buy extra power from gas companies who are also fielding increased demand for household heating. The last time it did so – after issuing its recent notice of insufficient system margin – it had to spend an extra £2.5m on power.

Outgoing boss Steve Holliday reckons this could happen a further 10 times this winter.

Four women working in a London office during the power cuts of 1973-74, which were caused by the miners’ strike. Photograph: Evening Standard/Getty Images

It may not be cheap or easy to get more out of the sub-sea interconnectors either. If France and the Netherlands are also feeling the chill, it will come down to who is willing to pay the most to get the electricity flowing their way.

All of these extra costs will trickle down on to household energy bills eventually.

Analysts warn of even greater pressure on the UK’s energy increasingly threadbare safety cushion in the next couple of years.

Peter Atherton, an energy analyst with stockbroker Jefferies, said: “It is self-evident that the UK power system is under increasing stress. Eventually that stress will manifest itself via security of supply events.

“Emergency measures that National Grid have put in place should be adequate for this winter. However, with four large coal stations closing ahead of next winter it is questionable whether existing measures will be enough.”

The coal-fired power stations are closing as the government struggles to meet the EU’s target of 15% renewable energy by 2020.

With plants such as these out of commission, the demand side balancing reserve and supplemental balancing reserve should come into their own.

However, they are yet to be renewed for next year, with the energy regulator scheduled to make a final decision later this month on whether to use and expand them.

“Ofgem is minded to extend use of these additional balancing services so they are also available to National Grid in 16/17 and 17/18 and is consulting on this decision. The consultation closes [on Thursday],” it said.

Wind is not driving the UK towards power blackouts | Chris Goodall and Mark Lynas

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National Grid said: “We believe the additional balancing services will be needed and used and we’re working with Ofgem to get approval to use the services next winter.

“We are doing the analysis for our more detailed outlook reports and will provide a timely update to the industry to help their market decisions.

“A lot can happen between now and winter 2016/17.”

Without an extension, according to Ofgem projections, Britain’s reserve margin could be wiped out entirely, leaving us reliant on the wind to blow to provide any buffer zone.

Beyond the next two years, Ofgem and the National Grid say the new capacity market, which will overhaul how suppliers are rewarded for making energy available, will consign blackout fears to the past.

National Grid bosses will get the chance to explain to MPs how they will keep the lights on, when they come before the energy and climate chance select committee on 24 November.

In the meantime, both the company and the regulator profess confidence that they have enough tools at their disposal to keep the lights on. Although there will be days when they are crossing their fingers.